Projection apparatus and key input device thereof

Abstract

A projection apparatus includes a projecting module, a key input device and a controlling unit. The projecting module generates an image light beam. The key input device includes a key unit and a decoding conversion unit coupled to the key unit. The key unit includes a plurality of keys. When at least one of the keys is pressed, the decoding conversion unit outputs an identifying signal to the key unit and performs a decoding operation according to the identifying signal sent back from the key unit, and outputs a controlling signal to the controlling unit accordingly. The controlling unit coupled to the projecting module is for receiving the controlling signal and driving the projecting module accordingly.

1 . A key input device used in a projection apparatus, the projection apparatus comprising a controlling unit, the key input device comprising:
 a key unit comprising a plurality of keys; and   a decoding conversion unit coupled to the key unit, wherein when at least one of the keys is pressed, the decoding conversion unit outputs an identifying signal to the key unit and performs a decoding operation according to the identifying signal sent back from the key unit, and outputs a controlling signal to the controlling unit accordingly.   
     
     
         2 . The apparatus according to  claim 1 , wherein the key unit includes a keypad row switching device and the decoding conversion unit comprises:
 an output port coupled to the keys, wherein the identifying signal is outputted from the output port; and   a plurality of input ports correspondingly coupled to the keys;   wherein when at least one of the keys is pressed, the identifying signal is outputted from the output port to the key, the key unit sends the identifying signal to a corresponding input port through the key, and the decoding conversion unit performs the decoding operation according to the corresponding input port.   
     
     
         3 . The apparatus according to  claim 1 , wherein the key unit comprises a keypad matrix switching device and the decoding conversion unit comprises:
 a plurality of output ports correspondingly coupled to the keys; and   a plurality of input ports correspondingly coupled to the keys;   wherein when at least one of the keys is pressed, the identifying signal is outputted from a corresponding output port to the key, the key unit sends the identifying signal to a corresponding input port through the key, and the decoding conversion unit performs the decoding operation according to the corresponding output port and the corresponding input port.   
     
     
         4 . The apparatus according to  claim 1 , wherein the decoding conversion unit uses a remote control transmitter integrated circuit (IC). 
     
     
         5 . The apparatus according to  claim 1 , wherein the decoding conversion unit comprises:
 a decoding unit coupled to the key unit, for performing the decoding operation according to the identifying signal, and outputting a decoding signal accordingly; and   a signal converting unit coupled to the decoding unit, for converting the decoding signal and outputting the controlling signal accordingly.   
     
     
         6 . The apparatus according to  claim 5 , wherein the decoding conversion unit comprises an oscillator for providing a clock signal, and the signal converting unit outputs the controlling signal according to the clock signal. 
     
     
         7 . A projection apparatus, comprising:
 a projecting module for generating an image light beam; and   a key input device comprising:
 a key unit comprising a plurality of keys; and 
 a decoding conversion unit coupled to the key unit, wherein when at least one of the keys is pressed, the decoding conversion unit outputs an identifying signal to the key unit and performs a decoding operation according to the identifying signal sent back from the key unit, and outputs a controlling signal to the controlling signal accordingly; and 
   a controlling unit coupled to the projecting module, for receiving the controlling signal and driving the projecting module accordingly.   
     
     
         8 . The apparatus according to  claim 7 , wherein the controlling unit receives the controlling signal through a General Purpose Input/Output (GPIO) port. 
     
     
         9 . The apparatus according to  claim 7 , wherein the key unit comprises a keypad row switching device and the decoding conversion unit comprises:
 an output port coupled to the keys, wherein the identifying signal is outputted from the output port; and   a plurality of input ports correspondingly coupled to the keys;   wherein when at least one of the keys is pressed, the identifying signal is outputted from the output port to the key, the key unit sends the identifying signal to a corresponding input port through the key, and the decoding conversion unit performs the decoding operation according to the corresponding input port.   
     
     
         10 . The apparatus according to  claim 7 , wherein the key unit comprises a keypad matrix switching device and the decoding conversion unit comprises:
 a plurality of output ports correspondingly coupled to the keys; and   a plurality of input ports correspondingly coupled to the keys;   wherein when at least one of the keys is pressed, the identifying signal is outputted from a corresponding output port to the key, the key unit sends the identifying signal to a corresponding input port through the key, and the decoding conversion unit performs the decoding operation according to the corresponding output port and the corresponding input port.   
     
     
         11 . The apparatus according to  claim 7 , wherein the decoding conversion unit uses a remote control transmitter integrated circuit. 
     
     
         12 . The apparatus according to  claim 7 , wherein the decoding conversion unit comprises:
 a decoding unit coupled to the key unit, for performing the decoding operation according to the identifying signal, and outputting a decoding signal accordingly; and   a signal converting unit coupled to the decoding unit, for converting the decoding signal and outputting the controlling signal accordingly.   
     
     
         13 . The apparatus according to  claim 12 , wherein the decoding conversion unit further comprises an oscillator for providing a clock signal, and the signal converting unit outputs the controlling signal according to the clock signal. 
     
     
         14 . The apparatus according to  claim 7 , wherein the controlling unit is a central processing unit (CPU).